Download ReBarUEFI Download | TechSpot
Download Free ReBarUEFI Download | TechSpot
The module is added to the UEFI firmware’s DXE volume so that it is executed on every boot. The ReBarDxe module replaces the PreprocessController function of the PciHostBridgeResourceAllocationProtocol with a function that checks for Resizable BAR capacity and then sets it to the size from the ReBarState NVRAM variable after running the original function.
The new PreprocessController function is later called during PCI enumeration by the PciBus module which will detect the new BAR size and allocate it accordingly.
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Claim
- (optional) 4G decoding enabled. See Enabling hidden 4G decoding wiki page if you can’t find an option for it. Without 4G decoding you will be limited to 1GB BAR and in some cases 512MB you can try to increase this up to 2GB by reducing TOLUD
- (optional) BIOS support for large BARs. There are patches to fix most problems related to this
Use
- Follow the Adding FFS Module wiki guide and continue through the steps. It covers adding the module and the additional modifications needed if necessary.
- After running the modded firmware, make sure 4G decoding is enabled and CSM is off.
- Then run ReBarState as found in releases (if you’re using Linux builds with CMake) and set the size of the size to be resized. In most cases you should be able to use 32 (unlimited) without problems, but you may need to use a smaller BAR size if 32 doesn’t work
- If Resizable BAR works for you, please reply to List of Working Motherboards so I can add it to the list. Most firmware will accept unsigned/patched modules with secure boot on, so you won’t have any problems running certain games.
- If you have problems after enabling Resizable BAR, see Common problems (and fixes)
UEFI patching
Most UEFI firmwares have problems handling 64-bit BARs, so several patches were created to fix these problems. You can use UEFIPatch to apply these patches located in the UEFIPatch folder. See the Using UEFIPatch wiki page for more information on using UEFIPatch. Be sure to check that the pad files have not been changed and if they are apply the solution
Worksheets
- Removal of <4GB BAR size limit
- Removal of <16 GB BAR size limit
- Removal of <64GB BAR size limit
- Prevent 64-bit BARs from being downgraded to 32-bit
- Increase MMIO space to 64 GB (Haswell/Broadwell). Full 512 GB/39-bit is not possible yet.
- Increase MMIO space from 16 GB to full use of 64 GB/36-bit range (Sandy/Ivy Bridge). Requires DSDT modification on some motherboards. See the DSDT Patching wiki page for more information.
- Remove NVRAM whitelist to resolve ReBarState GetLastError: 5
- Fix USB 3 ports not working in BIOS with 4G decoding enabled (Ivy Bridge/Haswell/Broadwell)
- X79 Above 4G Decoding fix
Build
Use the provided buildffs.py script after cloning inside an edk2 tree to build the DXE driver. ReBarState can be built on Windows or Linux using CMake.
What is new
- Add CMOS reset detection
- CMOS reset should now disable Resizable BAR so you won’t have any boot issues after doing one. This works by checking if the system date is before 2023.